The present invention relates to anchor point devices, systems and methods for use in fall protection, and, especially, to mobile, overhead anchoring devices, systems and methods for use by personnel working at an edge, for example, the leading edge of a construction project or other structure.
Fall protection systems including safety harnesses and lanyards are commonly used to protect persons subjected to the potential of a fall from a height. Typically, a lifeline or lanyard is connected to an overhead anchorage point on a structure. However, in many cases (for example, leading edge work and work on the highest completed deck of a construction project), suitable overhead fall protection anchorage may not exist.
For example, FIG. 1 illustrates a worker 10 positioned at the leading edge of a portion of a deck of a construction project. In general, in extending the deck in a horizontal direction, lateral I-beams 20 (for example, aluminum I-beams) or other lateral support structures are placed at a predetermined spacing (for example, 16 inches) on beams 30 extending from a more formed or completed section or portion 40 of the decking, and supported by some structure extending to the floor below.
Under current practice, workers such as worker 10 are not anchored via a lifeline when working at a leading edge of a construction project as illustrated in FIG. 1 because there is no suitable anchorage point available. In that regard, as the deck under construction is typically the highest deck of the construction project, there is no suitable overhead anchorage point.
It is possible to “horizontally” anchor worker 10 to an anchorage point A positioned generally horizontally or laterally from worker 10 on a completed portion of the decking via a generally horizontally extending lifeline or lanyard 50 which can be part of a retractable lanyard system 60 (see, for example, U.S. Pat. No. 5,771,993, the disclosure of which is incorporated herein by reference). An example of a commercially available, retractable lanyard is the MILLER MIGHTYLITE self-retracting lifeline, available from Dalloz Fall Protection of Franklin, Pa. Retractable lanyard systems such as retractable lanyard system 60 typically include a breaking mechanism (not shown in FIG. 1) to arrest the fall of a mass or person attached thereto once an internal, tensioned drum (not shown in FIG. 1) reaches a predetermine angular velocity (corresponding to a certain rate of fall). The drum of self-retractable lanyard system 60 is preferably is under adequate rotational tension (provided, for example, by a spring) to reel up excess extended lifeline 50 without hindering the mobility of the user 10. Lanyard 50 can, for example, be connected to a D-ring 70 of a safety harness 80 worn by worker 10.
Although a lifeline anchorage as illustrated in FIG. 1 may provide some level of protection for construction workers working on the leading edge of deck placement or working on the highest completed deck of a construction project, workers falling from the edge of a deck who are tied off to such a lifeline anchorage can suffer injuries if, for example, they swing during or after the fall or if they strike a lower deck or structure extending to the floor below. For example, the worker can be in free fall until at least that time when lanyard 50 falls a distance X to contact the edge of forward beam 20. In general, only after lanyard 50 contacts beam 20 will the drum of retractable lanyard system experience an angular velocity corresponding to the rate of fall. The fall of worker 10 may not, therefore, be arrested before worker 10 strikes something below. In that regard, lower decks are often only approximately eight to twelve feet below an upper deck under construction. Moreover, with or without use of retractable lanyard system 60, worker 10 can swing into an obstruction during the fall or after the fall has been arrested. The worker could also strike the support structure for beams 30. Non-retracting lanyards can be substituted for retractable lanyards, but non-retracting lanyards tend to either limit the mobility of the worker, or allow excessive free fall that is more likely to cause a strike on structure below the work surface.
It is desirable, therefore, to develop devices, systems and methods that reduce or eliminate the above problems.